Polyhedral Combinatorics in Combinatorial Optimization

Polyhedral combinatorics is a subarea of combinatorial optimization of increasing practical importance. It deals with the application of the theory of linear systems and linear algebra to combinatorial problems. The paper is not intended as a survey on polyhedral combinatorics but it reviews some of the main concepts and proof techniques.     

Inferences about the parameters of a time series model with changing variance

Summary We consider the problem of making inferences about the parameters of a time series model when there is the possibility of a discrete variance change at an unknown time point. For this we obtain the posterior distributions of the parameters and of the variance ratio.     

Examining product managers’ job satisfaction and performance using selected organizational behavior variables

The product management form of organization has been around for quite a while; yet little empirical research has been done on product managers. This article reports a study of product managers and some organizational behavior factors which contribute to their job satisfaction and job performance. These factors include centralization of decision making, job structure, job scope, role ambiguity, and role conflict. Finally, several suggestions are made for creating an environment more conductive to having product managers who are satisfied with their jobs.     

Informal group influence among situationally/dispositionally-oriented consumers

Consumer susceptibility to reference group influence has been demonstrated for certain products and buying situations. This article reports a study designed to determine if reference group influence varies between consumers classified as situationally-oriented and dispositionally-oriented. Results indicate a considerable difference between the two groups. Independence Health Plan     

Spotlight on free beds

What happens in today's hospitals when keeping the faith with donors clashes with fiscal politics? An enterprising assistant attorney general asked that question and turned up some disquieting answers.     

Avoid the breakdowns between planning and implementation

There are eight areas in a business plan where energy is often wasted. Here's how to spot the gaps that prevent plans from being put into action.     

Measuring cost savings in the operating room: a matter of FOCUS (follow-through, obsolescence, control, utilization, standardization)

In summary, changes came slowly at first in the OR. The biggest inventory reduction came about a year after the effort had begun. It would seem that tackling obsolescence, standardizing products, etc. would give an initial "big chunk" savings, with small amounts coming later as inventories are lowered. What we expected did not occur, due to the inherent nature of practices and what was customarily being used. For example, previously, some equipment purchases were paid for by purchasing product, which resulted in long-term commitments and high supply costs. The OR at times seemed more like a process of managing change, not just supplies. FOCUS is a daily process. How many times can you afford to overlook this process? How often are the mistakes of the past repeated? In review, we suggest this simple outline: Follow-through (review each case from start to finish), Obsolescence (schedule inventories every six months), Control (achieve inventory management by adjusting PAR levels to needs), Utilization (utilize product/equipment with your control), and Standardization (standardize products and measure results).